"Jim Macklin" wrote in message
news:jvdmg.49354$ZW3.19866@dukeread04...
Unless the wing is producing lift, there is no rotation to
reduce the angle of attack. If the wing was really stalled,
the airplane would fall flat,

A "really stalled" wing (that is, one that is past the critical angle of
attack) still produces lift. But even if it didn't, the tail could still
weathervane the plane nose-down into the relative wind.

if it was spinning it would be
a flat spin, but if was fully stalled, it would be a deep
stall and would not rotate the nose down and it would stay
in the stall.

Under normal conditions, neither the wing or the tail fully
stalls.

When you execute a normal stall in many typical GA planes, the wing can
certainly stall fully (that is, it reaches and exceeds the critical angle of
attack). That's why you lose altitude rapidly in a stall, even in a plane
that is maintaining level flight when just slightly above stall speed. The
tail, however, does not stall when you execute a normal stall.

If the center of pressure was located at the same location
as the CG, there would be no moment or force to cause
rotation.

That's true if you're referring to the CP of the whole plane (not just to
the CP of the wings). But when the wings stall and the plane descends,
shifting the relative wind, the tail's (upward) lift increases, shifting the
plane's CP backward and pitching the nose downward. (See John Denker's
excellent explanation of decalage and angle-of-attack stability:
http://www.av8n.com/how/htm/aoastab.html#sec-teeter)

--Gary